The recent mobile phone market has been in an active changeover from the conventional second-generation system to the third-generation system that is capable of providing communications of still higher speed and higher quality. In accordance with this, there has been an expansion in the service area of the third-generation system.
With the second-generation system, most of the areas are covered basically by outdoor base stations that are placed on the rooftops of buildings or the like, and indoor base stations are placed to secure the area only for the underground and a part of large-scaled buildings which are not covered by the outdoor base stations.
However, the frequency of 2 GHz band used in the third-generation system provided by a part of communication companies is higher than the frequency used in the second-generation system, so that there is a large loss caused due to transmission or diffraction of the radio waves. Thus, buildings where the radio waves cannot reach the inside thereof (non-sensitive buildings) are being built even at this point where the outdoor base stations for the third-generation system are basically set ready for the first round. Considering the use condition of the mobile phone users, however, most of outgoing and incoming calls are sent and received indoors. Therefore, expansion of the service into the indoor areas has become the recent central topic for the third-generation system.
For dealing with the non-sensitive area inside the buildings, an indoor base station may be provided inside the non-sensitive building, or a small-scaled base station may be provided in the peripheral area of the non-sensitive building as the countermeasure to be taken. As mentioned above, actions taken for dealing with the non-sensitive area by taking some kinds of countermeasures are referred to as non-sensitive area countermeasures. The communication company needs to make an investment to take a non-sensitive area countermeasure, so that it is necessary for the communication company to make sure which building is worth the investment. However, there are a large number of non-sensitive buildings for the third-generation system particularly in urban districts. Thus, it takes a lot of time and effort to specify the building that is worth the investment (to place a base station) among those buildings.
In order for the communication company to determine the building that is worth the investment among the number of non-sensitive buildings in an effective way, it is desirable to quantize the effects for the communication company, which may be obtained by taking the non-sensitive area countermeasure indoors, and to put the priority order based on the quantized effects. However, there is no technique provided for the tools used in the conventional RAN designing, for quantizing the effects for the communication company, which may be obtained by taking the non-sensitive area countermeasure.
Examples of the conventional RAN design tools are Atoll (a product of Forks Inc.), A-SVS (a product of ACTIX), and Capesso (a product of Symena). These tools are used for designing RAN that is already decided to be built, optimization and maintenance of RAN that is already being used, etc. Therefore, although a part of the tools has a function of calculating the “investment” made for the non-sensitive area countermeasure, such as calculating the cost for the equipment to be placed, those tools are not provided with a function of quantizing the effect for the communication company, which may be obtained by taking the non-sensitive area counter measure.
Further, although Patent Document 1 discloses a method for designating a potential site that needs to take a countermeasure by the use of demographic statistics, traffic statistics, or the like, it does not disclose a method for quantizing the effect obtained by placing the base station as in the conventional technique described earlier.
Furthermore, turning to the designing tools for networks other than RAN, there is Ativa Research Tool (a product of Telecom petition). This tool performs analysis and estimation of a next-generation network while considering time/spatial elements. This tool is provided with a function of estimating a profit as the effect obtained by building a network. However, this is a tool targeting at a large-scaled area such as a city level or a district level, so that it cannot be applied to estimation on the basis of a building level for the indoor non-sensitive area countermeasure that is the issue herein.
Patent Document 1: Japanese Unexamined Patent Publication 2003-309868